What it 500 Internal Server Error: It means the server encountered an unexpected issue that caused it to fail in fulfilling the request.
Causes: Error with the server configuration files, or corrupted plugins that affect server files.
Fix 1
Replace the .htaccess file code with a new one with the Basic WP in https://wordpress.org/support/article/htaccess/
Fix 2
Increase Memory Limit PHP Variable - How to edit PHP variables
Fix 3
Deactivate plugins - How to deactivate plugins manually
Like all technical areas, errors will happen. It’s important to note a few things regarding using the fixes in this article:
- Check DNS & make sure everything is proper before resorting to changing files.
- When handling any files, make sure to follow this guide: How to handle WordPress files